1. Field of the Invention
The present invention relates generally to security lighting, and in particular to a light fixture for a parking facility with a detection system for detecting parking space status, moving vehicles and personnel in the vicinity of the parking space.
2. Description of the Related Art
Lighting fixtures are used for environmental control, i.e., illumination, and a variety of different designs have previously been developed to meet the requirements of particular applications.
Light fixtures are commonly installed in various structures for security purposes. For example, parking garages comprise a class of structures which typically require illumination for safety and security. Since parking garages are often used during the hours of darkness, artificial illumination is desirable to reduce collision risks, enhance safety, etc. Moreover, parking garages are sometimes regarded as risky from the standpoint of personal attack. Such risks can be enhanced by the vulnerability of motorists as they enter and leave their vehicles and are thus preoccupied with retrieving vehicle keys, locking and unlocking vehicle doors, loading or unloading items in the vehicle, etc. Such activities tend to preoccupy motorists, and assailants have been known to time their attacks for such moments of vulnerability.
Another security problem with parking structures is that vehicles parked therein afford numerous hiding places for would-be assailants. Other hazards associated with parking structures include collision risks associated with vehicles entering and leaving parking spaces. For example, when a vehicle backs out of a parking space, its driver's rearward vision is often limited, thus increasing the chances of a collision with a vehicle in the drive aisle. Another common problem encountered by motorists in parking structures relates to locating available spaces. Considerable amounts of unnecessary driving often occur as motorists traverse the drive aisles in large parking structures seeking empty parking spaces.
A partial solution to safety and security issues associated with parking structures is to provide illumination by mounting light fixtures therein. However, the normal design standards for parking structure illumination require only relatively low illumination levels, e.g., about 0.5 foot candles per square foot.
Light fixtures have previously been used for security purposes by coupling them with motion detection switching systems. For example, U.S. Pat. No. 5,381,323; No. 5,434,764 and No. 5,442,532 disclose lighting fixtures with motion or proximity detectors. Such lighting fixtures can be used in areas in which illumination is desired when personnel are present. They tend to discourage intruders and would-be assailants by depriving them of the cover of darkness.
Motion sensing electronics are well known in the art. For example, the Ravas U.S. Pat. No. 3,459,961 discloses a movement responsive light control means. The Ravas '961 patent motion sensor utilizes a doppler shift in a transmitted signal frequency to detect movement and thus trigger a firing circuit, which in turn switches a load (e.g., a light) to an on condition. Other sensor systems currently available utilize sonar and infrared technology to detect objects and object movement.
Heretofore there has not been available a detection system for a light fixture with the safety and security advantages of the present invention. The present invention addresses some or all of the foregoing safety and security issues as they relate to parking structures and lighting system therefore.